Answer is: 0,0095 mol of hydrogen gas will be produced in reaction.
Chemical reaction: Ca + 2HCl → CaCl₂ + H₂.
m(Ca) = 0,38 g.
n(H₂) = ?
n(Ca) = m(Ca) ÷ M(Ca).
n(Ca) = 0,38 g ÷ 40 g/mol
n(Ca) = 0,0095 mol.
from reaction: n(Ca) : n(H₂) = 1 : 1.
n(H₂) = n(Ca) = 0,0095 mol.
n - amount of substance.
I believe the answer is C
Answer:
The answer is B an open system allows energy and mass to move in and out of it
Hope it helps
<span> </span> <span>V = nRT/P =
(0.875)(0.082057)(273)/(1) = 19.6 L</span>
the oxidation states of the elements before and after the reaction is;
Pb oxidation state changes from 0 to +2
SO₄²⁻ ion there's no change in the oxidation state during the reaction
Au oxidation state changes from +3 to 0
reduction reactions are when there's a decrease in the oxidation state of the species
oxidation reactions are when theres an increase in the oxidation state of the species
the element where there's a decrease in oxidation state is Au.
Therefore Au gets reduced.
answer is B) Au